1. Field of the Invention
The invention relates to character presence detection systems within character recognition systems; and, more particularly, to character presence detection systems which operate to locate characters within a line of characters.
2. Description of the Prior Art
Reference is made to U.S. Pat. No. 4,013,999 issued to Erwin et al on Mar. 22, 1977 and entitled "Single Read Station Acquisition For Character Recognition". The Erwin patent shows and describes a line finding technique for utilization with a single read station for minimizing the amount of video which is required to be stored. Although the Erwin patent does show line finding, it does not show character presence detection.
Character presence detection is accomplished by the recognition unit as shown in U.S. Pat. No. 3,761,876 issued to Flaherty and Hale on Sept. 25, 1973 and entitled "Recognition Unit For Optical Character Reading System". The system shown in the Flaherty patent is that character presence is determined by observation of the output of a plurality of masks. The outputs of the masks are monitored for the output having the largest amplitude over a number of attempts at character recognition during which the data being provided to the mask is shifted.
It is also known in the art to divide lines of data into character segments based on the assumption that all the characters are of the same width. That is, the length of the line is divided by some predetermined number which is equal to the number of characters assumed to be present in line. Although this particular method of character presence detection is useful, it does not lend itself to situations where the character width is variable and some of the characters may be overlapping, touching, and smudged characters.
None of the prior constructions known in the art shows a method and system for character detection which is capable of detecting characters within a line of characters represented by a serial data stream by utilizing iteration process to determine which characters should be combined and based on the results of certain criterion which are applied to each scan of the data stream. Further, none of the prior constructions shows a method and system for character detection which utilizes certain derived numbers which are utilized to test the characters combined during the iteration process to determine if any of the characters are too large and should be divided. Also, none of the prior constructions show a method and system for character detection for finding characters within a line which locates voids between words and distinguishes from gaps between characters.